Currently, counterfeits increasingly sell across all business day by day. To prevent counterfeiting and reuse of counterfeits, various technologies to prevent counterfeit and falsification using braille, hologram or special inks have been developed.
However, these technologies still do not eradicate counterfeits because counterfeit or falsification is committed through counterfeit experts, and counterfeit or falsification is difficult for users to discriminate. Moreover, the reuse of products such as packaging boxes and containers to which braille or hologram is attached poses a problem, making it more difficult to eradicate counterfeits.
In this circumstance, there is an earlier report of an anti-counterfeit structure using a plasmonic amplification phenomenon induced by metal nanowire and metal film with an up-conversion (UC) material that absorbs infrared light and emits visible light interposed between (Adv. Funct. Meter. 2016, 26,7836). However, this structure has a structural method for preventing the reuse, but to this end, it needs to use extra pollutants, and because there is no special encoding, attempts to reproduce may be made.
Therefore, in view of these many problems, there is a demand for the development of low-cost, easy-to-manufacture anti-counterfeit technology to prevent the reuse by discouraging attempts to reproduce through pattern encoding, and easily discriminate counterfeit.